More from WebMD

April 17, 2008 -- A novel immune-suppressing drug appears to effectively
treat moderate to severe plaque psoriasis, according to a new
report published in The Lancet.

Psoriasis is a chronic inflammatory skin
condition that affects about 7.5 million Americans, according to the National
Institutes of Health. Plaque psoriasis is the most common type of
psoriasis.

Cyclosporin, a type of drug called a calcineurin inhibitor, is among the
most effective short-term treatments for plaque psoriasis. However, concerns
that the drug can lead to kidney damage has limited its long-term use. Newer drugs offer alternatives, but they are often cost
prohibitive, and few data exist on their long-term safety and
effectiveness.

ISA247 is a new type of calcineurin inhibitor taken by mouth that is
designed to treat autoimmune conditions, including psoriasis. Canada-based
researcher Kim Papp and colleagues evaluated the drug's effectiveness in a
phase III clinical trial involving 451 patients 18 to 65 years old. To be
eligible for the study, the patient had to have plaque psoriasis on at least
10% of their body.

Papp's team divided the patients into four groups and randomly assigned them
to different doses of the medication or a placebo. The study participants took
the medicine twice a day.

Researchers considered the drug effective if it caused a 75% reduction in
the psoriasis area and severity index score (PASI 75) at week 12.

At 12 weeks, researchers found that the higher the dose of ISA247, the
better it performed. The drug was effective in 47% of those who received the
highest dose, compared with only 16% of those on the lowest dose and 4% in the
placebo group. After following participants for another 12 weeks, the
researchers demonstrated continued efficacy.

The researchers noted
temporary mild to moderate reduction in kidney function in some patients
in the study. The most common adverse events were headache, upper respiratory tract infection, and
inflammation of the nose and throat.